On my Mac, iPhone and iPad I am using the Creative Cloud Photography subscription. Related to photoshop Lightroom Mobile, I have some questions:
1.1 No, you have to open LrM
1.2 No, Apple don't let LrM delete from the iPhone library. So yes, this is a pain and you have to remember to do it yourself.
As far as I know, there isn't a limit for the LrMobile part of this plan, which is why you don't find it documented. I thought there was a 2gb limit for cloud storage other than LrM.
Wow, that was fast! Thanks for your answers.
On the iPad, I just found an information on the bottom left after I opened "settings". It says "97 of 114 GB" remains free, so maybe there is an (unofficial) limit after all. It seems like a lot, though.